title: Weather entrainment and multispectral diel activity rhythm of desert hamsters.
abstract: The circadian rhythm of animals is an adaptation to predictable variation in environmental conditions. Multiple internal oscillators may allow animals to cope with environmental oscillations in different frequencies. Heat stress and dramatic differences between night and day temperatures are the main selective pressures of the diel activity of desert mammals, particularly small-sized rodents. We tested the hypotheses that the diel activities of desert hamsters (Phodopus roborovskii) would be entrained by ambient humidity and temperature. We predicted that increases in night temperature and humidity would improve the propensity to perform activities of the hamster. We observed hourly activities of desert hamsters under semi natural conditions for 24 consecutive hours, with seven replicates in 7 different days. We fit generalized linear mixed models to observed proportions of active hamsters, temperatures, and relative humidity. Observed diel activities of desert hamsters consisted of three harmonic oscillations in the periodicities of 24 h, 12 h, and 6 h, respectively. Furthermore, probabilities to perform activities were positively related to night temperature and humidity. Therefore, the diel activities of desert hamsters are synchronized by atmospheric humidity, temperatures, and environmental cues of ultradian fluctuations.
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Chaoyang District, Beijing 100101, China.
authors.forename: Xinrong
authors.initials: X
authors.lastname: Wan
authors.forename: Xinjie
authors.initials: X
authors.lastname: Zhang
authors.forename: Yingjun
authors.initials: Y
authors.lastname: Huo
authors.forename: Guiming
authors.initials: G
authors.lastname: Wang
mesh_terms: D000223:Adaptation, Psychological / Q000502:physiology; D000465:Algorithms; D000818:Animals; D002681:China; D002940:Circadian Rhythm / Q000502:physiology*; D006224:Cricetinae; D003627:Data Interpretation, Statistical; D003889:Desert Climate; D006813:Humidity; D009043:Motor Activity / Q000502:physiology*; D017111:Phodopus / Q000502:physiology*; D017440:Photoperiod; D014887:Weather
keywords: Circadian rhythm; Humidity; Inner Mongolia; Phodopus roborovskii; Ultradian rhythm